Device for controlling electrically-driven stages, lifts, and the like.



A. BGHMERL DEVICE FOR CONTROLLING'ELEGTRIGALLYDRIVEN STAGES, LIFTS, AND THE LIKE. I

' APPLICATION IILED FEB. 21, 1908.

Patented Mar. 23, 1909.

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DEVICE EOE CONTROLLING ELEGTRIOALLY DRIVEN STAGES, LIFTS, AND THE LIKE.

APPLIUA'IION FILED FEB. 21, 1908.

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v I J l I I l l I l l I l I I I I I I I I l l l l I l l l A. BUHMER. DEVICE FOR CONTROLLING ELEGTRIGALLY DRIVEN STAGES, LIFTS, AND THE LIKE.

APPLICATION FILED FEB. 21, 1908. 91 6,259.

d aam h ii liFiJ \qw 5% a w Q m J W g v I A. BGHMER. v DEVICE FOR CONTROLLING ELEGTRIOALLY DRIVEN STAGES, LIFTS, AND THE LIKE.

' APPLICATION FILED FEB. 21, 1903.

Patented Meir. 23 19.09.

; 4BHEETS-SHEET 4.

Of 704m UNITED STATES PATENT OFFICE.

AUGUST 'BOHMER, OF MAGDEBURG, GERMANY.

Specification of Letters Patent.

Patented March 23, 1909.

Application filed February 21, 1908. Serial No. 417,058.

To all whom. it may concern:

Be it known that I, AUGUST Bonnnn,

. manufacturer, a subject of the King of Prussia, German Emperor, residing at N o. 9 Insleberstrasse, Magdeburg, in the Kingdom of Prussia, German Em ire, have invented certain new and usefu Improvements in Devices for Controlling Electrically Driven Stages, Lifts, and the Like, of which the followlng is a specification, reference being had therein to the accompanying drawing.

The subject-matter of the present invention is a method and device by which the travel of electrically operated stages on carriages, the cages of hoists, or the like, is to be automatically limited, so that the electric circuit is broken andithe stage or the like is fixed in every desired previously determined position as to height, without action on the part of the attendant.

In accordance with the invention the switch for the main conductor is operated directly, and in accordance with the new method in such a manner-that the switch is held in the closed position, in which it is placed against the action of a spring, by a detent or stop, until the latter is released in the end position of the stage by a controlling means operated from the driving motor, so that the spring-pressed switch returns into its commencing position.

The device may be employed for continuous current as well as for polyphase current;

in the former case a starting resistance may be inserted in addition; this is preferably connected with the switch and inserted again automatically after the circuit is broken. 7

The stop is released by a traveling nut which'in its end positions corresponding to .those of the stage moves mechanism directly connected with the locking device of the main switch, so that this stop is operated and 4 not the switch. The arrangement of special releasing gear independent. of the carriage and operated directly by the motor has the advantage that the motor can be cut out of circuit and stoped in a short space of time.

In order that the invention may be clearly understood, reference is made to the accompanying drawing in which embodiments are relplresented by way of example and in w 'ch:

Figure 1 is an elevation partly in section showing the device with two uncoupling levers, and Fig. 2 is a transverse section through the same. Fig. 3 1s an elevation of a modified form, and Figs. 4 and 5 are an elevation and cross-section respectively of an auxiliary switch of the starting resistance for continuous current, whereas Figs. 6 and 7 are diagrams of connections for continuous and polyphase current respectively.

Referring to the drawing, on the base-plate l'there are attached all the parts of the device, so that the latter forms a'whole closed in itself which can be built in independently of the carriage. The base-plate carries edestals 2 in which there rests the ho low switch-shaft 3, in the hollow of which flat torsion springs 4 are arranged. On said shaft there are situated insulation bushings '6 for the switch-levers 26 which are formed T-shaped in the front part and carry contacts 7; the latter lie on the contact-shoes 8 which are on, but insulated from, the base plate. A pair of shoes 8 belongs to each of the three switch-levers. A brake-disk 9 and the hand-wheel 10 are arranged at the front end of the shaft; behind the front pedestal there is situated a locking-disk 11 provided with two notches 12 into which two pins 13 can alternately snap, In order to enable this, the two notches 12 are dis laced with respect to one another both in t e direction of the periphery of the disk and also the breadth, so that whenever the disk rotates always only one notch becomes connected with the appertaining pin. At the lower ends of the pins there are attached two two'- armed disconnecting levers 14 which must always return into their commencing positions on account of the tension of the springs 15. The ends. of these levers carry beveled noses 16 against which a wheel 18 on the switch-nut 17 runs, whereby the levers are rocked. The nut 17 has on both sides pivots 19 on which pulleys 20 can rotate, and the latter, on their part, run on the guide 21 which is formed, for example, of U-shaped iron. The guide 21 is attached to the pedestals 22 of the spindle 23, the latter being rotated by the pulley 24 from the electric motor. The end of the springs 4 is attached in a rectangular piece 25; the latter, on its part again, rests in a correspondin cavity 1n the. base-plate, so that the "en of the springs does not participate in the rotation.

In order to prevent the current being repeatedly switched on in the same direction, a safety device is provided consisting of a spring-pressed slide 30 which carries a small central lug 32 and two large lateral noses 29.

Against the central lug there lie pins 31 situated on the locking disk 11. there are also pawls 28 which can lie on the noses 29. The employment of the disconnecting levers enables the switch-nut to be moved beyond the end position.

The device operates in the following manner:In the disconnected position of the stage, the switch-lever is inv the position I. If the stage is to be moved upward, for example, by rotating the hand-wheel 10, the switch-lever 26 is brought into the circuitclosmg position II in which one of the two pins 13 snaps into the appertaining notch 12, so that the switch-lever now remains in the position in which the circuit is closed. At the same time the nut 17 begins to travel to the right-hand for example, and at last contacts the nose 16 whereby the lock is released, and the lever 14 is rotated against the tension of its spring 15 and lever 26 returns into its commencing position. Now if the current is to be switched on again, this is not possible in the same direction, since the pawl 28 would have previously fallen on the nose 29 of the safety-slide 30. The switch must therefore be rotated in the opposite direction, so that it comes into position 111. In this case the one pin 31 which is on the disk 11 lies against the axle 32 of the safety slide 30, and brings the same into its extreme right-hand position. At the moment when the circuit is closed, the second releasing pin 13 which has hitherto been lying on the periphery of the disk 11, snaps into its groove 12 and locks the switch, while the nut 17 moves toward the other end, so that the previously described operation is again repeated in the end position.

The device re resented in Fig. 3 consists of a nut 35 Wide likewise runs on a spindle 23 driven by the motor. The nut rests in a guide 36 revoluble around the spindle 23 ,and this guide carries stops 37 for the end positions of the nut. The end of the guideframe is formed as an eccentric 38 .on which there runs a pulley 40 journaled in a pin'39.

- switch 26 is uncoupled b the nut 35 hitting against the stop 37 at t e end of its movement. At this moment it is thus prevented from moving farther, and the frame 36 is therefore rotated against the tension of the spring 43. The part of the eccentric farthest from the center then moves upward, the pin 39 is raised and the detent p1n13 lowered,

On the latter so that the switch is liberated. The spring 43 simultaneously returns the frame again into its normal position.

When continuous current is employed, it is necessary in addition when starting the motor to cut out resistances successively from the circuit. In order to efl'ect this at the suitable moment in the present device, a variable resistance is connected with the releasing pin 13, this resistance being so con structed that it can be operated only in definite positions of the main switch, as the carriage must generally be attended by unskilled workmen. For switching resistance out 01 circuit, a contact-slide 45 is employed which is moved over the contacts 46. The slide is on an insulated rod 47 which has a notch both on its upper and lower side, these notches being arranged displaced relatively to one another in a horizontal direction. With the releasing pin 13 there is also connected a two-armed lever 49 provided at its free end with two leaf-springs 50 which clasp the rod 47 in such. a manner that one of them can always engage in its appertaining notch. In the normal position in which the detent pin 13 occupies its lowest osition, the lower spring 50 engages in the ower notch 48; in this case all the resistances are connected in circuit. It is then not possible to push rod 47 inward; to do so the spring would have to be broken oil by force. If current is switched on, on the contrary, and the detent-pin 13 has arrived in its highest position, the lower spring leaves its groove, whereas the upper lies on the rod 47. The latter can now be pushed longitudinally against the tension of the spring 52 and accordingly the resistances can be cut out of circuit; In the end position the upper spring 50 sna s into its appertaining groove and locks t e slide. 11' the movement of the stage has finished, the detent lpin 13 returns into its normal position, so t at the upper spring also releases the: rod 47 and the latter automatically returns into its. commencing position in consequence of the pressure of the spring 52.

Fig. 6 is a diagram of connections for continuous current, and Fig. 7 shows that for polyphase current. The characteristic feature in these connections is that the second and third contacts are connected cross-wise, so that by simply reversing the switch, the circuit is also reversed. The two front contacts are connected with one another. In the case of continuous current the one pole of the motor is connected to one of these contacts, a starting resistance 46 being inserted between the motor and the contact, whereas the shunt is conneetedto the two rear contacts 8.

What I claim-as my invention and desire to secure by Letters atent is:

1. In a device for automatically controlling the movement of electrically driven stages on carriages, or hoisting-devices the combination of a mechanically operated lock adapted to be released by a regulator operated in the end positions of the stage by sition.

2. In a device of the type described, the

combination of a base-plate, a shaft carrying a switch-lever fastened thereto, a spring;

tending to keep said s itch-lever in its open position, a disk having notches fixed on said shaft, one or more spring-pressed detents:

'! base-plate, sald shde having a central lug and a nose at each side thereof, said lug belng against said disk adapted to engage in said notches and hold the disk in a plurality of closed positions of the saitch-lever, and disconnecting means adapted to be actuated by an electric motor for nithdran ing said detents from said notches, \i hereby the SV itchlever returns automatically to its open position.

3. In a device of the type described, the combination of a hase plate, a shaft carrying a itch-lever fastened thereto, a spring tending to keep said s itch-lever inits open position, a disk having notches fixed on said shaft, one or more spring-pressed detents against said disk adapted to engage in said notches and hold the disk in tao closed positions of the s itch-lever, pedestals on'saidbase-plate, a screw ed spindle carrying a pulley revoluble in said pedestals, a nut carrylng a Wheel on said spindle, and two levers each I carrying a nose at one end and connected at the other end with one of said detents, said noses being adapted to be engaged by said i wheel. 1 4. In a device of the type described, the i combination of a base-plate, a shaft carrying a sivitch -lever fastened thereto, a spring tending to keep said switch-lever in its open position, a disk having notches fixed on said shaft, a spring-pressed detent against said 1 i disk adapted to engage in one of said notches I and hold the disk in a closed position of the 1 1 to be actuated by an electric motor for Withdrawing said detent from said notches i whereupon the switch-lever returns automatically to its open position, pins on said disk, pawls on saiddisk, and a slide on said adapted to be contacted by said pins and each nose being adapted to be contacted by and to hold one of said pawls.

In a device of the type described, the combination with a base-plate, and a shaft carrying a switch-lever fastened thereto, of a disk having two notches fixed on said shaft, two pins on said disk, two pawls on said disk, and a slide on said base-plate, said slide having a central lu and a nose at each side thereof, substantial y as shown for the purpose specified.

In Witness whereof I have hereunto set my hand in presence of two a itnesses.

AUGUST BOHMER.

Witnesses J OHANNA GRUNOW, HANS EYCK.

switch-lever, disconnecting means adapted 

